Gravity-battery electrode.



P. T. MACNAMARA. GRAVITY BATTERY ELECTRODE. APPLICATION FILED APR. 6.Isle.

PATRICK T. MACNAMARA, OF NEW YORK, N. Y., ASSIGNOR TO TEE WESTERN UNIONTELEGRAPH COMPANY, OF NEW YORK, N. EL, A. CORPORATIOI-I OF NEW YORK.

GRAVITY-BATTERY ELECTRODE.

3h225,3el6.

Specification of Letters Patent.

Patented lrlay 8, 1917.

I Application filed April 6, 1916 Serial No. 89,280.

To (all whom it m (13 concern: v

Be it known that I, PATRICK T. Machi- NARA. a British subject, and aresident of the borough of lv l anhattan, city of hew York, county ofNew York. and State of New York. have invented certain new and usefulGraiity-Battery Electrodes, of which the following is a specification.

My invention relates to electrodes for primary batteries and the like,particularly gravity batteries, and comprises an improved form ofelectrode which has numerous advantages, as l'iereinafter pointed out.

The object of my invention is to improve the construction oihbattervelectrodes, par ti ularly negative electrodes of gravity cells. toobtain larger contact surface and greater electrical contact with thesolution, to obtain lower internal resistance, to avoid accumulation ofhydrogen on the surface of the electrode. to obtain greater evenness ofsurface current density, more even and smoother wear, to avoid prematurefalling off of any sector or limb of the electrode.

to provide an electrode which shall remain more nearly clean and lesssubject to local action and which need not be removed from the solutionfor cleaning, and to provide an electrode which shall .be moreeconomical and shall give longer life with less labor than is the casewith former'electrodes.

I will now proceed to describe my invention with reference to theaccompanying drawings and will then point out the novel features inclaims:

Figure 1 shows a central vertical section of a battery of the gravitytype provided with my improved electrode, such electrode being shown inpart in section and in part in elevation.

Fig. 2 shows a bottom view of the electrode.

In the drawings 1 designates the battery jar, and 2 the positiveelectrode, and 3 the usual solution.

4 designates the negative electrode, en:- bodying my invention. Thisnegative electrode, 4. ionsists of an outer rim portion'5 of triangularcross-section, the point of the triangle, being downward. such rimhaving a diametral portion 6 also of triangular cross-section, andvhaving further a plurality of limbs 7 extendi'ilig radially inwardtoward, but not in Contact with, the diainknown to me. and that there isless tendency with this electrode for saturation of and crystallizationin the upper portion of the solution. i find further that this electrodegives lower internal resistance of the cell as a whole, and greatersteadiness of current output; these qualities being due, probably, inlarge measure at least, to the fact that since all of the transversesectional shapes of the electrode are triangular with the apex of thetriangle downward, hydrogen evolved during the operation of the celldoes not cling to the electrode, but passes up freely and is dissipatedat the surface of the liquid; for which reason large portions of thesurface of this electrode are not blanketed by hydrogen accumulations,as is commonly the case when prior forms of electrodes are used. Owingboth to the freedom of the electrode from hydrogen accumulations. and tothe practically uniform distribution oi the material of the electrodelll'llOllQ'll the cross-sectional area of the cell, this electrode givesgreater evenness of surface current density, and wears evenly andsmoothly without premature falling oti of any sector or limb. It retainsits triangular cross-smttion practically throughout its entire life. andhas longer life and requires less attention than any other electrodeknown to me. In the past the negative electrodes of gravity cells haveusually been made of Zinc; but I prefer to make this electrode ofcast-iron; for while the voltage of a copper-iron cell is somewhat lessthan that of a copper-zinc cell, the greater cheapness of the ironelectrode as compared with the zinc electrode. together with the factthat the surface of the iron electrode remains cleaner. and is lesssubject to local action, renders the iron electrode much preferable tothe zinc electrode.

, cross-section with the What I claim. is:

1. A battery electrode comprising a membe having a plurality of spacedlimbs with connecting portions, such limbs and the connecting portionsbeing of triangular point of the triangle downward.

2. A battery electrode comprising a peripheral portion having limbsextending" therefrom such peripheral portion and limbs being oftriangular cross-section with the point of thetriangle downward.

3. A battery electrode comprising a pcripheral portion having limbsextending inwardlytherefrom such peripheral portion, such limbs being oftriangular cross section with the point of the triangle downward.

4. A battery having a peripheral rim with a diametral member and withlimbs extending radially inward toward the center, but not contactingwith each other or with the said diametral member, such rim, diametralmember and limbs all of triangular cross-section with the point of thetriangle downward.

electrode comprising a body A battery electrode comprising a bodyprovided with means for supporting -it within a battery jar orcontainer, the crosssectional figure of such electrode being in generalone affording a more or less sharp lower edge with sides extendingobliquelyupward, the section being devoid of fiat horizontal lowersurfaces upon which hydrogen may collect.

(S. A battery electrode comprising a body having a rim with limbsextending therefrom, such rim and extending limbs being each of across-sectional figure having a more or less sharp lower edge with sidesextending obliquely upward, the section being devoid of flat horizontallower surfaces upon which hydrogen may collect.

In testimony whereof I have signed this specification in the scribingwitnesses.

PATRICK T. MAGNAMARA Witnesses:

M. H. STOCKBERGER, PAUL H. F RANKE.

presence of two sub

